Using Manual Lenses (M42 Screwmount, M , K) on Pentax DSLRs F--

RioRico · 12-02-2011, 04:24 PM

What Adam said.

Originally posted by neil1

doe not have ring, the lens is a da 18-250 pentax

I've tried using non-expensive TCs on my DA18-250. They suck. I get better results just by cropping the picture.

kshapero · 12-04-2011, 07:04 AM

Originally posted by Marc Sabatella

The only things you should need to set are the same things you would have had to set on the K20D - the "Use Aperture Ring" option in the menu, and be sure to be in M mode.

I have good success in AV mode.

Marc Sabatella · 12-04-2011, 03:25 PM

Sure, if you only want to shoot wide open. If you actually want to control the aperture with a manual K-mount lens, you must use M mode. Otherwise the aperture stays wide open.

Dean31 · 12-27-2011, 06:42 PM

I came on here to ask about manual focusing with screw mount lenses, but after reading I have another question.

1) I have some Takumar lenses for indoor ice skating/gymnastics. Can I use 'catch in-focus' with these on my Kx? I've read the manual and tried, but am not having any luck. I experience alot of operator error still, so I wanted to make sure I wasn't missing something. Any other focusing tips would be appreciated as well.

2) I just read the section on metering and found it helpful, thank you. My question is about your comment at the bottom on Av setting. Generally speaking, when would I use this setting over the "M" (manual) setting? How can it help me or when could I use it to my advantage?

I'd love to have a capable zoom, but can't afford the lenses it would take to put out the kind of pictures I want to get (it's really bad lighting). The Taks are doing a really nice job....albeit without the conveniences of auto anything or any zoom (not to mention I'm a noob and barely know how to use them yet, much less get the most out of them). Thanks in advance!

RioRico · 12-27-2011, 07:49 PM

1) Yes, you can use CIF (catch in focus). BUT... you need to safely short the contacts on the body mount. With many M42s, that's easily done: put a bit of metal duct-repair tape (NOT cloth-plastic duck tape!) on the lens base. BUT... some Taks and other M42s have narrow bodies and won't cover the contacts. You can maybe put a bit of metal foil over the contacts, and it might work, or maybe not.

2) M(anual) mode works with any lens. But the Green button won't stop-down the lens for metering and exposure, as it will with PK lenses. Setting the camera to any Auto mode with an M42 lens, the camera defaults to Av mode. In either M or Av, you use the lens' apertures ring to control the iris opening. Which is best? I'll use Av for "just shooting", and M when reading off a gray card or otherwise setting the exposure for incident (ambient) light, not reflected light.

You maybe know some of the tricks for shooting action in low light:

* Boost the ISO -- digital noise can be fixed in PP, motion blur can't.
* Prefocus on a known location and wait for the action to reach there.
* Shoot subjects moving towards you, not moving across the visual field.
* Use wider lenses -- lower shutter speeds are usable. And don't forget SR.

Does this help?

MSD · 12-27-2011, 08:18 PM - **1 Like**

My Super Tak 50/1.4 has easily replaced my 18-200 as my standard lens. Hasn't come off the camera since June (except for extension tubes).
K20D makes a great combination with it. Limited (actually no) zoom range is nothing to worry about. Any prime user will make that clear.
For me, it's a bonus. Anyway, enjoy your manual lenses, everyone!

**mgvh** · 01-22-2012, 04:49 PM

I'm having real troubles using my M50 f1.7 with my K-x and the pop-up flash.
Is there any quick way of getting exposure set properly?
I'm within the parameters as defined by the equations on pg 160 of the K-x manual, but it is so hard to get a pic that is not completely blown out.
I also have an A50 f2, so I thought I would shoot with that first and copy those setting on the M50. For a good exposure using the flash with the A50, the K-x rightly calculated for a good exposure:
1/180 sec at ISO 800 using f2
That was a complete blow out on the M50, and I finally (after much trial and error) got an acceptable shot using:
1/180 sec at ISO 100 using f8 and turning down the flash by 2 steps.

SO:

Is there a quick way to get proper exposure using a M lens with the popup flash?
Why should there be such a difference between the settings used by the A50 and M50?

Thanks for any help.

Mike Cash · 01-22-2012, 04:58 PM

Because the A lens can communicate electrically with the camera and set the aperture to work with the flash; the M lens can't.

You need to know the flash's output is GN13 (meters, ISO100) and calculate and set the aperture yourself for correct flash exposure.

Divide the GN by the subject distance to get aperture. So a subject four meters away would be 13 divided by 4 so somewhere between f2.8 and f4 would be about right. Compensate accordingly when using different ISO settings.

The A lens can use P-TTL. The camera fires a pre-flash and can adjust flash output. With an M lens it is full blast or nothing. So when you shot with the A lens it is almost certain that the flash was firing with less than full power, which would account for why the M was blown out at the same settings....the flash output was higher, although you couldn't notice it.

**mgvh** · 01-22-2012, 06:02 PM

@Mike Cash: Thanks. That makes sense...
I was using the EXIF info from the A50 shot, so I had hoped that they would get me in the ballpark. The EXIF didn't indicate anything about reduction in flash power, but I suspect that might not be indicated simply because I did not adjust it.

I did a few more shots w/ the M50, and it seems that I can get close to the right exposure by simply setting it 1/180 and using the ISO calculations to get the right f-stop, but I still have to close it down another full stop (or reduce ISO) to get a better exposure.

Thanks again.

Marc Sabatella · 01-23-2012, 10:39 AM

The reason the Exif doesn't record the flash power output is because there is no standardized way of recording that info. Might be buried in the maker notes somewhere.

I find that even though I *can* get a good flash expsoure with an M lens through the old fashioned method of stopping down to the aperture suggested by distance to subject divided by the flash's guide number, the full power flash is really harsh looking and blinding to subjects. Not worth the effort.

troy24 · 02-19-2012, 05:11 PM

My K100D Super will not fire with a Sigma DL 100-300 lens..why?

Adam · 02-19-2012, 05:36 PM

Originally posted by Adam

First, if your camera won't fire, set "Allow aperture setting other than A" to 2 (allowed) in the custom function menu.

Read the first post

Since that 100-300mm lens is AF, all you need to do is put the aperture ring in the "A" position and use the e-dials to control the shutter speed and aperture.

michael markey · 02-22-2012, 06:08 AM

Well this has been a useful thread.
I do equestrian photography twice a week with either a film Contax with an 80/1.4 or two Leica M`s for the closer stuff.
I was considering a DSLR using the Zeiss Contax lenses but didn`t want to go down the Canon route.

From reading this thread I could also consider using my Pentax 100/2.8 or my 120/2.8 on a Pentax DSLR with the additional benifit of in body stabilisation .
I had no idea that they would still meter ...and give me focus confirmation aswell.
Looks like a no brainer .....esp as I love the two Pentax lenses.
Thanks for the info.

Michael

abacus07 · 04-26-2012, 08:18 PM

Shouldn't the instructions in the first post be updated?

Quote:

Set your camera to M mode using the mode dial (your camera won't fire in other modes*)

It will take a picture in other modes (at least Av) but the result will be the common overexposed photo that so many talk about at first.

**Basset** · 04-27-2012, 12:01 PM

Originally posted by michael markey

Well this has been a useful thread.
I do equestrian photography twice a week with either a film Contax with an 80/1.4 or two Leica M`s for the closer stuff.
I was considering a DSLR using the Zeiss Contax lenses but didn`t want to go down the Canon route.

From reading this thread I could also consider using my Pentax 100/2.8 or my 120/2.8 on a Pentax DSLR with the additional benifit of in body stabilisation .
I had no idea that they would still meter ...and give me focus confirmation aswell.
Looks like a no brainer .....esp as I love the two Pentax lenses.
Thanks for the info.

Michael

This is why I still shoot Pentax - in-body stabilization and easy use of legacy lenses.

01-22-2012, 04:49 PM	#112
mgvh Site Supporter Join Date: Sep 2010 Location: MD Photos: Gallery \| Albums Posts: 1,029	Flash with M50 on K-x I'm having real troubles using my M50 f1.7 with my K-x and the pop-up flash. Is there any quick way of getting exposure set properly? I'm within the parameters as defined by the equations on pg 160 of the K-x manual, but it is so hard to get a pic that is not completely blown out. I also have an A50 f2, so I thought I would shoot with that first and copy those setting on the M50. For a good exposure using the flash with the A50, the K-x rightly calculated for a good exposure: 1/180 sec at ISO 800 using f2 That was a complete blow out on the M50, and I finally (after much trial and error) got an acceptable shot using: 1/180 sec at ISO 100 using f8 and turning down the flash by 2 steps. SO: Is there a quick way to get proper exposure using a M lens with the popup flash? Why should there be such a difference between the settings used by the A50 and M50? Thanks for any help.

01-22-2012, 04:58 PM	#113
Mike Cash Veteran Member Join Date: Jan 2007 Location: Japan Photos: Gallery Posts: 6,950	Because the A lens can communicate electrically with the camera and set the aperture to work with the flash; the M lens can't. You need to know the flash's output is GN13 (meters, ISO100) and calculate and set the aperture yourself for correct flash exposure. Divide the GN by the subject distance to get aperture. So a subject four meters away would be 13 divided by 4 so somewhere between f2.8 and f4 would be about right. Compensate accordingly when using different ISO settings. The A lens can use P-TTL. The camera fires a pre-flash and can adjust flash output. With an M lens it is full blast or nothing. So when you shot with the A lens it is almost certain that the flash was firing with less than full power, which would account for why the M was blown out at the same settings....the flash output was higher, although you couldn't notice it. Last edited by Mike Cash; 01-22-2012 at 05:04 PM.

02-19-2012, 05:36 PM	#117
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594 Original Poster	Originally posted by Adam First, if your camera won't fire, set "Allow aperture setting other than A" to 2 (allowed) in the custom function menu. Read the first post Since that 100-300mm lens is AF, all you need to do is put the aperture ring in the "A" position and use the e-dials to control the shutter speed and aperture. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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12-02-2011, 04:24 PM	#106
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	What Adam said. Originally posted by neil1 doe not have ring, the lens is a da 18-250 pentax I've tried using non-expensive TCs on my DA18-250. They suck. I get better results just by cropping the picture.

12-04-2011, 07:04 AM	#107
kshapero Veteran Member Join Date: Feb 2007 Location: South Florida, USA Photos: Gallery \| Albums Posts: 437	Originally posted by Marc Sabatella The only things you should need to set are the same things you would have had to set on the K20D - the "Use Aperture Ring" option in the menu, and be sure to be in M mode. I have good success in AV mode.

12-04-2011, 03:25 PM	#108
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Sure, if you only want to shoot wide open. If you actually want to control the aperture with a manual K-mount lens, you must use M mode. Otherwise the aperture stays wide open.

12-27-2011, 06:42 PM	#109
Dean31 Junior Member Join Date: Nov 2011 Photos: Albums Posts: 27	I came on here to ask about manual focusing with screw mount lenses, but after reading I have another question. 1) I have some Takumar lenses for indoor ice skating/gymnastics. Can I use 'catch in-focus' with these on my Kx? I've read the manual and tried, but am not having any luck. I experience alot of operator error still, so I wanted to make sure I wasn't missing something. Any other focusing tips would be appreciated as well. 2) I just read the section on metering and found it helpful, thank you. My question is about your comment at the bottom on Av setting. Generally speaking, when would I use this setting over the "M" (manual) setting? How can it help me or when could I use it to my advantage? I'd love to have a capable zoom, but can't afford the lenses it would take to put out the kind of pictures I want to get (it's really bad lighting). The Taks are doing a really nice job....albeit without the conveniences of auto anything or any zoom (not to mention I'm a noob and barely know how to use them yet, much less get the most out of them). Thanks in advance!

12-27-2011, 07:49 PM	#110
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	1) Yes, you can use CIF (catch in focus). BUT... you need to safely short the contacts on the body mount. With many M42s, that's easily done: put a bit of metal duct-repair tape (NOT cloth-plastic duck tape!) on the lens base. BUT... some Taks and other M42s have narrow bodies and won't cover the contacts. You can maybe put a bit of metal foil over the contacts, and it might work, or maybe not. 2) M(anual) mode works with any lens. But the Green button won't stop-down the lens for metering and exposure, as it will with PK lenses. Setting the camera to any Auto mode with an M42 lens, the camera defaults to Av mode. In either M or Av, you use the lens' apertures ring to control the iris opening. Which is best? I'll use Av for "just shooting", and M when reading off a gray card or otherwise setting the exposure for incident (ambient) light, not reflected light. You maybe know some of the tricks for shooting action in low light: * Boost the ISO -- digital noise can be fixed in PP, motion blur can't. * Prefocus on a known location and wait for the action to reach there. * Shoot subjects moving towards you, not moving across the visual field. * Use wider lenses -- lower shutter speeds are usable. And don't forget SR. Does this help?

12-27-2011, 08:18 PM - 1 Like	#111
MSD Senior Member Join Date: Dec 2010 Location: Sydney Photos: Gallery \| Albums Posts: 163	My Super Tak 50/1.4 has easily replaced my 18-200 as my standard lens. Hasn't come off the camera since June (except for extension tubes). K20D makes a great combination with it. Limited (actually no) zoom range is nothing to worry about. Any prime user will make that clear. For me, it's a bonus. Anyway, enjoy your manual lenses, everyone!

01-22-2012, 06:02 PM	#114
mgvh Site Supporter Join Date: Sep 2010 Location: MD Photos: Gallery \| Albums Posts: 1,029	@Mike Cash: Thanks. That makes sense... I was using the EXIF info from the A50 shot, so I had hoped that they would get me in the ballpark. The EXIF didn't indicate anything about reduction in flash power, but I suspect that might not be indicated simply because I did not adjust it. I did a few more shots w/ the M50, and it seems that I can get close to the right exposure by simply setting it 1/180 and using the ISO calculations to get the right f-stop, but I still have to close it down another full stop (or reduce ISO) to get a better exposure. Thanks again.

01-23-2012, 10:39 AM	#115
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	The reason the Exif doesn't record the flash power output is because there is no standardized way of recording that info. Might be buried in the maker notes somewhere. I find that even though I can get a good flash expsoure with an M lens through the old fashioned method of stopping down to the aperture suggested by distance to subject divided by the flash's guide number, the full power flash is really harsh looking and blinding to subjects. Not worth the effort.

02-19-2012, 05:11 PM	#116
troy24 New Member Join Date: Feb 2012 Posts: 2	My K100D Super will not fire with a Sigma DL 100-300 lens..why?

02-22-2012, 06:08 AM	#118
michael markey Senior Member Join Date: Oct 2010 Location: Lancashire Posts: 136	Well this has been a useful thread. I do equestrian photography twice a week with either a film Contax with an 80/1.4 or two Leica M`s for the closer stuff. I was considering a DSLR using the Zeiss Contax lenses but didn`t want to go down the Canon route. From reading this thread I could also consider using my Pentax 100/2.8 or my 120/2.8 on a Pentax DSLR with the additional benifit of in body stabilisation . I had no idea that they would still meter ...and give me focus confirmation aswell. Looks like a no brainer .....esp as I love the two Pentax lenses. Thanks for the info. Michael

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04-26-2012, 08:18 PM	#119
abacus07 Veteran Member Join Date: Oct 2010 Location: Taiwan Photos: Gallery \| Albums Posts: 1,075	Shouldn't the instructions in the first post be updated? Quote: Set your camera to M mode using the mode dial (your camera won't fire in other modes*) It will take a picture in other modes (at least Av) but the result will be the common overexposed photo that so many talk about at first.

04-27-2012, 12:01 PM	#120
Basset Site Supporter Join Date: Aug 2011 Photos: Albums Posts: 340	Originally posted by michael markey Well this has been a useful thread. I do equestrian photography twice a week with either a film Contax with an 80/1.4 or two Leica M`s for the closer stuff. I was considering a DSLR using the Zeiss Contax lenses but didn`t want to go down the Canon route. From reading this thread I could also consider using my Pentax 100/2.8 or my 120/2.8 on a Pentax DSLR with the additional benifit of in body stabilisation . I had no idea that they would still meter ...and give me focus confirmation aswell. Looks like a no brainer .....esp as I love the two Pentax lenses. Thanks for the info. Michael This is why I still shoot Pentax - in-body stabilization and easy use of legacy lenses.